Description: This native perennial grass is ¾–2¾' tall and develops tufts of unbranched leafy culms. In sunny habitats, this grass is taller and more stout, while in shaded habitats it is shorter and more delicate. The culms are light green, slender, and glabrous. About 6-8 alternate leaves occur along the length of each culm. The leaf blades are 1-6 mm. across and 2-10" long; they are medium green and hairless. The leaf sheaths are medium green, hairless, and open. At the junction of each blade and sheath, there is a ligule that is white and membranous. The nodes along each culm are green and swollen.
The culm of each fertile shoot terminates
in an inflorescence about 3-12" long and half as much across; this
inflorescence is often as long as the rest of the shoot. It consists of an airy
panicle spikelets that is much branched. The rachis (or central axis) of this
panicle is slender, hairless, and tends to zigzag along its length between
whorls of 2-3 branches. Terminal branchlets with spikelets often develop toward
the middle of larger branches; these branches are usually quite divergent,
especially for fertile shoots growing in shaded habitats. Each spikelet
consists of a pair of glumes and a single lemma with a floret; the inner palea
is absent or insignificant. The glumes are 2-3 mm. long, light green,
lanceolate, and strongly keeled; one glume is slightly larger than the other.
The lemma is 1-2 mm. long, light green, and oblong-ovate; it is shorter than
the glumes. In each spikelet, the prominent glumes resemble a pair of tiny
claws. The blooming period usually occurs during the late summer or early fall.
Pollination is by wind. The inflorescence turns tan when the grains ripen. The
root system is fibrous. Sometimes, this grass forms small colonies by reseeding
itself.
Cultivation: This grass can
adapt to a fairly broad range of growing conditions. It tolerates full sun to
light shade, moist to dry conditions, and soil containing loam, clay loam, and
rocky material. For a cool-season grass with a C3 metabolism, it is slow to
develop as most vegetative growth occurs during the summer, rather than the
spring. 
Range & Habitat: Upland
Bent is common in southern Illinois, occasional in central Illinois, and
uncommon or absent in the northern part of the state. Habitats include rocky
upland woodlands, mesic woodlands, thinly wooded bluffs, wooded slopes,
woodland openings, prairie swales, dolomite prairies (in NE Illinois), and
gravelly seeps. In woodlands, this species is often found on decayed tree
stumps or near the base of deciduous trees. In sunny habitats, where it is less
common, this grass prefers areas with more ground moisture. The size and
appearance of Upland Bent is highly variable across different
habitats.
Faunal Associations:
Little information is currently available about floral-faunal relationships for
Agrostis spp. (Bent Grasses). The caterpillars of the following skippers
are known to feed on the foliage of Bent Grasses, although not exclusively:
Amblyscirtes vialis (Common Roadside Skipper), Hesperia leonardus
(Leonard's Skipper), and Hylephila phyleus (Fiery Skipper). Another
insect that feeds on Bent Grasses is Chaetocnema denticulata (Toothed
Flea Beetle). Bent Grasses are palatable to many mammalian herbivores and
readily eaten by horses and livestock.
Photographic Location: A decayed tree stump in Busey
Woods, Urbana, Illinois. Toward the middle of the above photograph, there is a
light green leafhopper perched on one of the stems.
Comments: This is a rather ordinary-looking grass
that blooms during the latter part of the growing season. Upland Bent and other
Agrostis spp. (Bent Grasses) have small delicate spikelets; each one
with 2 prominent glumes and a smaller lemma. The spikelets of some Bent Grasses
have an inner palea near the lemma (which is hard to see), while Upland Bent
lacks this structure. Unlike some other species in this genus, Upland Bent also
lacks awns on its lemmas. Two similar species, Agrostis hyemalis (Tickle
Grass) and Agrostis scabra (Rough Tickle Grass), have terminal
branchlets of spikelets toward the tips of the larger branches. In contrast,
Upland Bent has some branchlets of spikelets toward the middle of the larger
branches, and the branching pattern of its panicles is often more divergent.
Another common name for this species is Autumn Bent.